#include<bits/stdc++.h>
#define hh << endl;
using namespace std;

int main() {
	int x, y;
	cin >> x >> y;
	if(x + y == 0 || x + y == 2) {
		cout << "Invalid"hh;
	} else if(x == 1) {
		cout << "Yes" hh;
	} else {
		cout << "No" << endl;
	}
	return 0;
}

